The present invention relates to an L-shaped channel wiring method for optimizing wiring configurations between circuit blocks in the layout design of a Very Large-Scale Integrated circuit (VLSI circuit).
Conventionally, there has been adopted a method for converting a horizontal line, i.e., a trunk into an L-shaped line obtained by combining horizontal and vertical line segments so as to minimize a wiring area for a straight line-shaped channel between VLSI circuit blocks.
U.S. Pat. No. 4,875,139 has disclosed an L-shaped channel wiring method in which a line segment in the direction along an L-shaped side, i.e., a trunk, and a line segment parallel to the middle angle direction of an L-shaped angle on the trunk, i.e., a branch line is drawn in mutually insulated separate wiring layers in a wiring region interposed between the L-shaped sides of two circuit blocks having terminals on their sides, and the trunk is connected to the branch line by a through-hole in the insulated layer at the intersection of the trunk and the branch line so that wiring is formed.
Referring to the conventional L-shaped channel wiring method, however, the bending of the trunk is not allowed. Consequently, the wiring region cannot fully be minimized.
More specifically, the trunk is formed by an L-shaped line comprised of one or two straight lines. Consequently, only one trunk is wired in a wiring region. As a result, the space between the circuit blocks is increased so that the wiring region is made larger.
It is an object of the present invention to convert a trunk into a polygonal line obtained by combining a line segment in the direction along an L-shaped side with a line segment parallel to the middle angle direction of an L-shaped angle so as to minimize the area of a wiring region.